Scheduling policies in multi-product manufacturing systems with sequence-dependent setup times and finite buffers

Abstract

Multi-product production systems with sequence-dependent setup times are typical in the manufacturing of semiconductor chips and other electronic products. In such systems, the scheduling policies coordinating the production of multiple product types play an important role. In this paper, we study a multi-product manufacturing system with finite buffers, sequence-dependent setup times and various scheduling policies. Using continuous-time Markov chain models, we evaluate the performance of such systems under seven scheduling policies, i.e. cyclic, shortest queue, shortest processing time, shortest overall time (including setup time and processing time), longest queue, longest processing time, and longest overall time. The impacts of these policies on system throughput are compared, and the conditions characterising the superiority of each policy are investigated. The results of this work can provide production engineers and supervisors practical guidance to operate multi-product manufacturing systems with sequence-dependent setups.

Keywords:

• manufacturing systems
• Markovian analysis
• throughput
• sequence-dependent setups
• scheduling policies

Acknowledgements

The authors are grateful to Mr. F. Hou of Intel China for valuable discussions and the helpful comments of the anonymous reviewers. This work was supported, in part, by NSF grant No. CMMI-1063656, the National Natural Science Foundation of China (grant No. 70771058/60834004), and the 863 Program of China (2008AA04Z102).